436 Phylum Arthropoda 



Family trypetidae 



NOTES ON BREEDING THE APPLE MAGGOT, 

 RHAGOLETIS POMONELLA 



Philip Garman, Connecticut Agricultural Experiment Station 



CONTINUOUS breeding of the apple maggot has until the last few 

 years been regarded as difficult and unsatisfactory. Fluke, how- 

 ever, demonstrated that flies might be reared successfully and, with 

 proper feeding, kept for a considerable length of time. Following this 

 work, an attempt was made at the Connecticut Agricultural Experiment 

 Station to rear the insect for experimental use, with the result that it 

 was bred continuously from August, 1934, to June, 1935, and many 

 flies were secured for experiment during the winter. 



Flies emerging in field cages are brought to the laboratory as soon 

 as they appear and are placed in5%xn%x7 inch cages with a glass 

 front and a cloth back. Honey and powdered yeast (4 parts honey to 

 1 part yeast) are smeared on the upper parts of the cage. After 

 mating, which takes place within a week (4 to 10 days), apples are 

 placed in the cage fcr oviposition. Green apple thinnings from com- 

 mercial orchards are used for this purpose, the stock being placed in 

 cold storage during July and removed from storage as needed. Apples 

 in which eggs are deposited are removed from cages frequently to pans 

 or battery jars for emergence of the larvae, which are then placed in 

 smaller glass jars and layered with sand for emergence of the adults. 

 On removal of the apples from oviposition cages they are put in a dry 

 place to prevent excessive rotting. The sand within emergence jars 

 must be kept moist during the pupal period, usually about one month, 

 and the flies removed promptly on emergence to cages, where they may 

 secure water and food. Much seems to depend on the quality of the 

 apples offered for oviposition, since green fruit appears to be much 

 more attractive to the flies than ripe or partly ripe fruit. Apples used 

 in spring after long storage are relatively unattractive, though more 

 attractive than fully ripe apples. The most difficult breeding period is 

 in spring before new apples can be obtained, and after the green fruit 

 reaches the point where it rots rapidly when taken from storage. The 

 ratio of increase in fall is likewise much better than during the winter 

 or spring, and has varied from 3 to 17 per individual in successful work. 

 Furthermore, it appears that flies from puparia hibernated in insectary 

 and refrigerators are much less vigorous and shorter lived than those 

 from fall-bred laboratory stock. 



The following table gives some of the data from fall breeding work 

 at the Connecticut Agricultural Experiment Station during 1934 in a 



